Re: queue_work from interrupt Real time preemption2.6.11-rc2-RT-V0.7.37-03

[Steven Rostedt <rostedt@goodmis.org>]

On Mon, 2005-02-14 at 12:40 -0800, Mark Gross wrote:
> I'm working on a tweak to the preepmtive soft IRQ implementation using work 
> queues and I'm having problems with a BUG assert when trying to queue_work.
> 
> Souldn't I be able to call queue_work form ISR context?

Yes, but not with interrupts disabled.
> 
> --mgross 
> 
> ---------------------------
> | preempt count: 00000001 ]
> | 1-level deep critical section nesting:
> ----------------------------------------
> .. [<c0140f5d>] .... print_traces+0x1d/0x60
> .....[<c01042a3>] ..   ( <= dump_stack+0x23/0x30)
> 
> BUG: sleeping function called from invalid context IRQ 20(2039) at kernel/rt.c
> in_atomic():0 [00000000], irqs_disabled():1

Here you have interrupts disabled. Since you are tweaking the softirq I
don't know your code, but the kernel should not schedule after turning
off interrupts, and the spinlocks under the PREEMPT kernel, may now
sleep (unless they are raw_spin_locks).  Here we also see that
queue_work calls spin_lock_irqsave.  I'm suspecting that you turned off
interrupts somewhere.

-- Steve